Bicycle exerciser



FIG. 1 is a front elevational view of a bicycle exerciser showing my new design;

FIG. 2 is a side perspective view thereof;

FIG. 3 is a side perspective view of the side opposite that shown in FIG. 2; and,

FIG. 4 is a rear elevational view thereof. 

The ornamental design for a bicycle exerciser, as shown and described. 